Effect of sling exercise therapy on surface electromyography and muscle thickness of superficial cervical muscle groups in female patients with chronic neck pain.

BACKGROUND: The persistence of symptoms in patients with chronic neck pain is considered to be associated with variation in the neck muscle structure and associated neuromuscular control. Sling exercise therapy (SET) has been demonstrated to relieve the symptoms of chronic neck pain, whereas it is controversial whether this benefit is correlated to altered neck muscle structure and associated neuromuscular control in the patients. OBJECTIVE: To investigate the effect of SET on cervical muscle structure (thickness) and associated neuromuscular control in patients with chronic neck pain. METHODS: Twenty-five patients with chronic neck pain were randomly assigned to the SET group (n= 12) or the control group (n= 13). The SET group received the SET intervention for 4 weeks, while the control group maintained normal activities of daily living. At baseline and after 4 weeks of intervention, Visual analogue scale and neck disability index were measured in both groups, and changes in the thickness of the superficial cervical muscles were assessed using musculoskeletal ultrasound. Surface electromyography (EMG) was adapted to assess the neuromuscular control of the neck while the participant was performing the cranio-cervical flexion test. RESULTS: At 4 weeks, the SET group had a significant reduction of RMS in both UT and SCM of EMG compared to the control group (p< 0.05). Regarding ultrasound, the SET group had significantly lower muscle thickness compared to the control group in both the rest position and the MVIC position (p< 0.05). There were no within-group differences in the control group (p> 0.05), while the SET group showed significant reductions in both RMS and muscle thickness (p< 0.05). CONCLUSION: 4-week SET was effective in reducing pain and dysfunction in patients with chronic neck pain, which may be related to improved neck muscle thickness and neuromuscular control of the neck.

Digital Loop-Mediated Isothermal Amplification-Based Absolute Methylation Quantification Revealed Hypermethylated DAPK1 in Cervical Cancer Patients.

The aberrant methylation of many genes has been reported to be associated with various carcinomas. Accurate detection of the methylation level could provide critical insights into the diagnostic analysis of diseases. Here, a sensitive HpaII-edited absolute droplet loop-mediated isothermal amplification (HEADLAMP) method based on methylation-sensitive restriction enzyme (MSRE) HpaII was developed for the digital quantification of DNA methylation. Methylation levels of the death-associated protein kinase 1 (DAPK1) gene that is associated with many cancers were studied using ß-actin as an internal reference. DAPK1 (2.5 pM) with 0.01% methylation (250 aM) can be detected with the conventional HpaII-edited LAMP assay. Using HEADLAMP, as low as 1% methylation level can be distinguished with an estimated limit of detection of 5 aM (ca. 3 copies/µL). Moreover, HEADLAMP can detect low levels of methylated DAPK1 in normal L-02 cells, while the conventional assay cannot. Finally, HEADLAMP was applied to the detection of DAPK1 methylation in 20 clinical tissue samples, which revealed hypermethylated DAPK1 in cervical cancer patients. We envisage potential applications of this robust, specific, and sensitive HEADLAMP assay in epigenetic studies and early clinical diagnosis.

Target induced reconstruction of DNAzymatic amplifier nanomachines in living cells for concurrent imaging and gene silencing.

A novel DNAzymatic amplifier nanomachine that is reconstructed in response to an mRNA input has been developed to enable the functions of concurrent sensitive mRNA imaging and activatable gene therapy in living cells.

Protein scaffolded DNA tetrads enable efficient delivery and ultrasensitive imaging of miRNA through crosslinking hybridization chain reaction.

Efficient intracellular delivery of nucleic acids to achieve sensitive detection and gene regulation is essential for chemistry and biology. Here we developed a novel protein scaffolded DNA tetrad, a four-arm DNA nanostructure constructed using streptavidin (SA) protein and four biotinylated hairpin DNA probes for efficient nucleic acid delivery and ultrasensitive miRNA imaging through crosslinking hybridization chain reaction (cHCR). DNA tetrads were easy to prepare and allowed precise control of the structure of the probes. DNA tetrads showed rapid intracellular delivery of DNA probes and high efficiency in lysosome escape by using confocal images for individual cells and flow cytometry for a large population of cells. cHCR allowed generating clumps of crosslinked hydrogel networks specifically to target miRNA, affording high sensitivity and spatial resolution for imaging. To our knowledge, this is the first time that HCR amplification has been realized in situ on nanostructures. Moreover, the FRET based design of cHCR conferred improved precision with the use of dual-emission ratiometric imaging to avoid false signals in biological systems. Intracellular imaging experiments further showed that DNA tetrad based cHCR could realize ultrasensitive and accurate miRNA imaging in living cells. Moreover, DNA tetrad based cHCR provided a potential tool for quantitative measurement of intracellular miRNA. The results suggested that this developed strategy provided a useful platform for nucleic acid delivery and low level biomarker imaging.

Single-base mismatch discrimination by T7 exonuclease with target cyclic amplification detection.

T7 exonuclease is reported for the first time to have high specificity in discriminating single-base mismatch and utilized for developing a target cyclic amplification biosensor strategy for sensitive SNP detection based on graphene oxide quenching of uncleaved probes.

Highly sensitive and selective strategy for microRNA detection based on WS2 nanosheet mediated fluorescence quenching and duplex-specific nuclease signal amplification.

MicroRNAs (miRNAs) play vital roles in physiologic and pathologic processes and are significant biomarkers for disease diagnostics and therapeutics. However, rapid, low-cost, sensitive, and selective detection of miRNAs remains a challenge because of their short length, sequence homology, and low abundance. Herein, we report for the first time that WS2 nanosheet can exhibit differential affinity toward short oligonucleotide fragment versus ssDNA probe and act as an efficient quencher for adsorbed fluorescent probes. This finding is utilized to develop a new strategy for simple, sensitive, and selective detection of miRNA by combining WS2 nanosheet based fluorescence quenching with duplex-specific nuclease signal amplification (DSNSA). This assay exhibits highly sensitive and selective with a detection limit of 300 fM and even discriminate single-base difference between the miRNA family members. The result indicates that this simple and cost-effective strategy holds great potential application in biomedical research and clinical diagnostics.

Activity-based DNA-gold nanoparticle probe as colorimetric biosensor for DNA methyltransferase/glycosylase assay.

We have developed a novel biosensor platform for colorimetric detection of active DNA methyltransferase/glycosylase based on terminal protection of the DNA-gold nanoparticle (AuNP) probes by mechanistically covalent trapping of target enzymes. This biosensor relied on covalent capture of target enzymes by activity-based DNA probes which created terminal protection of the DNA probes tethered on AuNPs from degradation by Exo I and III. This biosensor has the advantages of having highly sensitive, rapid, and convenient detection due to its use of the homogeneous assay format and strong surface plasmon absorption. Because the activity-based probes (ABPs) are mechanistically specific to target enzymes, this strategy also offers improved selectivity and can achieve the information about both abundance and activity of the enzymes. We have demonstrated this strategy using a human DNA (cytosine-5) methyltransferase (Dnmt 1) and a human 8-oxoguanine glycosylase (hOGG 1). The results reveal that the colorimetric response increases dynamically with increasing activity of the enzymes, implying a great potential of this strategy for DNA methyltransferase/glycosylase detection and molecular diagnostics and drug screening. Our strategy can also be used as a promising and convenient approach for visualized screening of ABPs for DNA modifying enzymes.